Predicting and reducing noise in a vibratory meter

Abstract

A vibratory meter ( 5, 1600 ) configured to predict and reduce noise in the vibratory meter ( 5, 1600 ). The vibratory meter ( 5, 1600 ) includes a sensor assembly ( 10, 1610 ) and a meter electronics ( 20, 1620 ) in communication with the sensor assembly ( 10, 1610 ). The meter electronics ( 20, 1620 ) is configured to provide a drive signal to a sensor assembly ( 10, 1610 ), receive a sensor signal from the sensor assembly ( 10, 1610 ) having one or more components, and generate a signal to be applied to one of the sensor signal and the drive signal to compensate for the one or more components.

We claim: 
     
       1. A vibratory meter ( 5 ,  1600 ) configured to predict and reduce noise in the vibratory meter ( 5 ,  1600 ), the vibratory meter ( 5 ,  1600 ) comprising:
 a sensor assembly ( 10 ,  1610 ); and 
 a meter electronics ( 20 ,  1620 ) in communication with the sensor assembly ( 10 ,  1610 ), the meter electronics ( 20 ,  1620 ) being configured to:
 provide a drive signal to a sensor assembly ( 10 ,  1610 ); 
 receive a sensor signal from the sensor assembly ( 10 ,  1610 ) having one or more components; and 
 generate a compensating signal to be applied to one of the sensor signal and the drive signal to compensate for the one or more components; 
 wherein the meter electronics ( 20 ,  1620 ) being configured to generate the compensating signal to be applied to one of the sensor signal and the drive signal comprises generating the compensating signal based on a system model of the sensor assembly ( 10 ,  1610 ). 
 
 
     
     
       2. The vibratory meter ( 5 ,  1600 ) of  claim 1 , wherein the system model of the sensor assembly ( 10 ,  1610 ) comprises a non-linear model of a transducer in the sensor assembly ( 10 ,  1610 ). 
     
     
       3. The vibratory meter ( 5 ,  1600 ) of  claim 1 , wherein the meter electronics ( 20 ,  1620 ) being configured to generate the compensating signal to be applied to the drive signal comprises generating the compensating signal to induce a motion in the sensor assembly ( 10 ,  1610 ) that substantially prevents the one or more components in the sensor signal from forming. 
     
     
       4. The vibratory meter ( 5 ,  1600 ) of  claim 1 , wherein the meter electronics ( 20 ,  1620 ) being configured to generate the compensating signal to be applied to the sensor signal comprises generating the compensating signal to cancel the one or more components in the sensor signal. 
     
     
       5. The vibratory meter ( 5 ,  1600 ) of  claim 1 , wherein the one or more components comprise at least one of intermodulation distortion signals and harmonic signals. 
     
     
       6. The vibratory meter ( 5 ,  1600 ) of  claim 1 , wherein the drive signal comprises a multi-tone drive signal including a drive tone and one or more test tones for verifying the sensor assembly. 
     
     
       7. The vibratory meter ( 1600 ) of  claim 1 , wherein the meter electronics ( 1620 ) comprises a compensating signal generator ( 1623 ) configured to generate the compensating signal to be applied to the one of the sensor signal and the drive signal to compensate for the one or more components. 
     
     
       8. A method of reducing noise in a sensor signal in a vibratory meter, the method comprising:
 providing a drive signal to a sensor assembly in the vibratory meter; 
 receiving the sensor signal from the sensor assembly in response to the drive signal, the sensor signal including one or more components; and 
 generating a compensating signal to be applied to at least one of the drive signal and the sensor signal to compensate for the one or more components; 
 wherein generating the compensating signal to be applied to one of the sensor signal and the drive signal comprises generating the compensating signal based on a system model of the sensor assembly. 
 
     
     
       9. The method of  claim 8 , wherein the system model of the sensor assembly comprises a non-linear model of a transducer in the sensor assembly. 
     
     
       10. The method of  claim 8 , wherein generating the compensating signal to be applied to the drive signal comprises generating the compensating signal to induce a motion in the sensor assembly that substantially prevents the one or more components in the sensor signal from forming. 
     
     
       11. The method of  claim 8 , wherein generating the compensating signal to be applied to the sensor signal comprises generating the compensating signal to cancel the one or more components in the sensor signal. 
     
     
       12. The method of  claim 8 , wherein the one or more components comprise at least one of intermodulation distortion signals and harmonic signals. 
     
     
       13. The method of  claim 8 , wherein the drive signal comprises a multi-tone drive signal including a drive tone and one or more test tones for verifying the sensor assembly. 
     
     
       14. The method of  claim 8 , wherein the compensating signal to be applied to the one of the sensor signal and the drive signal to compensate for the one or more components is generated by a compensating signal generator in a meter electronics of the vibratory meter. 
     
     
       15. A method of predicting and reducing noise in a sensor signal in a vibratory meter, the method comprising:
 determining an output signal from a non-linear model of a sensor assembly of the vibratory meter, the output signal being in response to an input signal having two or more components; and 
 adjusting a filter to attenuate one or more components in the output signal. 
 
     
     
       16. The method of  claim 15 , wherein adjusting the filter to attenuate the one or more components in the output signal comprises adjusting a frequency of one or more stop-bands of a magnitude response of the filter to be substantially centered at the frequencies of the one or more components in the output signal. 
     
     
       17. The method of  claim 15 , wherein adjusting the filter to attenuate the one or more components in the output signal comprises adjusting an attenuation of at least one stop-band to reduce the one or more components to a desired amplitude. 
     
     
       18. The method of  claim 15 , wherein adjusting the filter to attenuate the one or more components in the output signal comprises reducing the number of taps of the filter. 
     
     
       19. The method of  claim 15 , wherein the non-linear model of the sensor assembly comprises a non-linear model of a transducer of the sensor assembly. 
     
     
       20. The method of  claim 15 , wherein the non-linear model of the sensor assembly is a gain-position model of the sensor assembly. 
     
     
       21. The method of  claim 15 , wherein the one or more components of the input signal comprises one or more tones spaced apart from each other. 
     
     
       22. The method of  claim 15 , wherein determining the output signal from a non-linear model in response to the input signal having two or more components comprises determining at least one of an intermodulation distortion signal and a harmonic signal in the output signal.